What was found
APROX 50 MINUTES INTO FLIGHT HAD MAIN DECK AFT LOOP A FAULT. FOLLOWED QRH WITH GOOD TEST. BUT THEN LATER REPEATED SMOKE WARNING FROM MAIN DECK AFT. FOLLOWED BY VISIBLE BLUE SMOKE HAZE IN COCKPIT AND LATERBY SMOKE WARNING FROM MAIN DECK MID 1 AND MID 2 ACCOMPLISHED EMERGENCY LANDING AT KOKC. AFTER LANDING ALL WARNINGS WENT AWAY. R & R 1 &2 COALESCER BAGS I.A.W. 21-51-16-03, NO CONTAMINATION FOUND. PERFORMED VISUAL INSPECTION OF NR 1 & 2 ENGINES FOR OIL LEAKS, NO LEAKS NOTED. CHECKED OIL LEVELS AND HYDRAULIC LEVELS AS REQUESTED BY MOCC NR 1 ENGINGE SERVICE WITH 3 QTS. CREW REPORTED THAT NR 1 ENG WAS AT MINIMUMS ON DEPT FROM MEM.REMOVED AND REINSTALLED NR 1 IP CHECK VALVE IAW 36-11-13-04 PER MOCC REQUEST. ACFT OK FOR CONTINUED SERVICE.